A Network Interface Controller (NIC)—which may be, for example, network interface circuitry, such as on a PCI card connected to a host computer via a PCI host bus—is typically used to couple the host computer to a packet network through at least one NIC interface, called a port. Recently, the growth in host virtualization has led to additional functionality being performed by virtualization-aware NICs. One class of such functionality is packet switching, which allows multiple virtual operating systems or guest operating systems on a host system to communicate with each other through a NIC attached to the computer system. A related standardization effort of virtual machine switching is under way.